As Bryan has said the parts book is very good at identifying where things like O rings or oil restrictors fit.
As you probably know the block base gasket fits on the crankcase, the larger four block seal rings fit in the groove on the underside of the block. You will need to use red rubber grease on them so they stay in place when you fit the block over the pistons. You also have the fiddly part of fitting the cam chain tensioner blades. You might find it helpful to read that section in my 500 project thread (Page 35) or another members thread.
Using the search facility on this site will also list posts where a subject has arisen before so you can be read a variety of solutions & outcomes.
